With the development and ever increasing highway use of large tractor-trailer combinations, it has become increasingly important to provide heavy duty couplings having safety locks insuring against inadvertent or accidental release of the trailer on the highways, a condition to be avoided at all costs. It is the general purpose of the present invention to provide such a coupling.
It is a further important object of the present invention to provide a pintle type trailer coupling provided with an automatic take-up for adjusting for hook and eye wear in order to prevent the development of a loose, sloppy fit between these two important components of the coupling.
Other important objects of the present invention are the provision of a pintle-type trailer coupling which is:
Particularly suited for use with dual drawbar trailer units.
Easy to couple and uncouple even though there is a load pulling against the pintle.
Easily mounted on the tailboard of the truck.
Shielded against entry of ice and snow in the winter, thus minimizing rusting of the moving parts of the coupling.
Easy to repair by replacement of worn or broken parts.
Easy to back into during the coupling operation.
The foregoing and other objects of the invention are provided by the provision of a truck-trailer coupling assembly comprising a truck-mounted housing having a pivotally mounted pintle hook for coupling to a cooperating eye mounted on the trailer.
The pintle hook is shiftable between open and closed positions. It is provided with a radially extending arm having a stop surface.
A first detent is pivotally mounted on the housing a spaced distance from the pintle hook. It is shiftable between an advanced position, wherein the pintle hook is closed, and a retracted position, wherein the pintle hook is open. It has a stop surface in abutting contact with the stop surface of the pintle hook arm when the pintle hook is in its closed position and the first detent is in advanced position. It also has an associated operating lever overlying the pintle hook body.
Resilient means bias the lever and associated first detent toward their advanced positions.
Cam means mounted in the housing between the pintle hook body and the lever cooperate with the resilient means in shifting the lever and associated first detent between their advanced and retracted positions, thereby permitting shifting of the pintle hook between its open and closed positions as required for the coupling and uncoupling operations.